﻿
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 
<title>HTML5 &amp; jQuery - Grayscale Image Hover</title> 
<style type="text/css"> 

#circle {
    width: 50px;
    height: 50px;
    -webkit-border-radius: 25px;
    -moz-border-radius: 25px;
    border-radius: 25px; 
}

body {
	background: #fff;
	color: #000;
	font: 14px/140% Arial, Helvetica, sans-serif;
	margin: 40px 0;
}
a {
	text-decoration: none;
	color: #86AEBB;
}
img {
	border: none;
}
h2 {
	font: bold 14px/110% Arial, Helvetica, sans-serif;
	margin: 0 0 30px;
	padding: 0 0 20px;
	color: #999;
	border-bottom: solid 1px #ccc;
	clear: both;
}
h3 {
	font: bold 16px/120% Arial, Helvetica, sans-serif;
	margin: 0;
}
#pagewrap {
	width: 948px;
	margin: 0 auto;
}
.item {
	width: 296px;
	margin: 0 0 30px 30px;
	float: left;
}
.item.first {
	clear: left;
	margin-left: 0;
}
.item img {
	opacity:0;
}
</style> 
<script src="/resources/js/jquery-1.4.2.min.js" type="text/javascript"></script> 
<script type="text/javascript"> 
	
	// $(".item img").css({"display":"none");
	
	// On window load. This waits until images have loaded which is essential
	$(window).load(function(){
		
		// Fade in images so there isn't a color "pop" document load and then on window load
		$(".item img").animate({opacity:1},500);
		
		// clone image
		$('.item img').each(function(){
			var el = $(this);
			el.css({"position":"absolute"}).wrap("<div class='img_wrapper' style='display: inline-block'>").clone().addClass('img_grayscale').css({"position":"absolute","z-index":"998","opacity":"0"}).insertBefore(el).queue(function(){
				var el = $(this);
				el.parent().css({"width":this.width,"height":this.height});
				el.dequeue();
			});
			this.src = grayscale(this.src);
		});
		
		// Fade image 
		$('.item img').mouseover(function(){
			$(this).parent().find('img:first').stop().animate({opacity:1}, 1000);
		})
		$('.img_grayscale').mouseout(function(){
			$(this).stop().animate({opacity:0}, 1000);
		});		
	});
	
	// Grayscale w canvas method
	function grayscale(src){
        var canvas = document.createElement('canvas');
		var ctx = canvas.getContext('2d');
        var imgObj = new Image();
		imgObj.src = src;
		canvas.width = imgObj.width;
		canvas.height = imgObj.height; 
		ctx.drawImage(imgObj, 0, 0); 
		var imgPixels = ctx.getImageData(0, 0, canvas.width, canvas.height);
		for(var y = 0; y < imgPixels.height; y++){
			for(var x = 0; x < imgPixels.width; x++){
				var i = (y * 4) * imgPixels.width + x * 4;
				var avg = (imgPixels.data[i] + imgPixels.data[i + 1] + imgPixels.data[i + 2]) / 3;
				imgPixels.data[i] = avg; 
				imgPixels.data[i + 1] = avg; 
				imgPixels.data[i + 2] = avg;
			}
		}
		ctx.putImageData(imgPixels, 0, 0, 0, 0, imgPixels.width, imgPixels.height);
		return canvas.toDataURL();
    }
	    
</script> 
</head> 
<body> 
<div id="pagewrap"> 
	<h1>HTML5 &amp; jQuery Grayscale Demo</h1> 
	<h2>Tutorial by <a href="http://www.webdesignerwall.com">Web Designer Wall</a> (<a href="http://www.webdesignerwall.com/tutorials/html5-grayscale-image-hover/">read article</a>). Coding by <a href="http://darcyclarke.me">Darcy Clarke</a>.</h2> 
	<div class="item first"> 
		<a href="http://themify.me"><img src="/resources/images/grayscale/themify.jpg" /></a> 
		<h3>Themify</h3> 
	</div> 
	<div class="item"> 
		<a href="http://icondock.com"><img src="/resources/images/grayscale/icondock.jpg" /></a> 
		<h3>IconDock</h3> 
	</div> 
	<div class="item"> 
		<a href="http://www.webdesignerwall.com"><img src="/resources/images/grayscale/webdesignerwall.jpg" /></a> 
		<h3>Web Designer Wall</h3> 
	</div> 
	<div class="item first"> 
		<a href="#"><img src="/resources/images/grayscale/koifish.jpg" /></a> 
		<h3>Koi</h3> 
	</div> 
	<div class="item"> 
		<a href="#"><img src="/resources/images/grayscale/phoenix.jpg" /></a> 
		<h3>Phoenix</h3> 
	</div> 
	<div class="item"> 
		<a href="#"><img src="/resources/images/grayscale/peacock.jpg" /></a> 
		<h3>Peacock</h3> 
	</div> 
	<div class="item first"> 
		<a href="#"><img src="/resources/images/grayscale/flow.jpg" /></a> 
		<h3>Flow</h3> 
	</div> 
	<div class="item"> 
		<a href="#"><img src="/resources/images/grayscale/webdesign136cover.jpg" /></a> 
		<h3>Web Designer</h3> 
	</div> 
	<div class="item"> 
		<a href="#"><img src="/resources/images/grayscale/sakura.jpg" /></a> 
		<h3>Sakura</h3> 
	</div> 
</div>
</body> 
</html>